1. Field of the Invention
The invention relates to a mechanism of a track ball which is used in an information processing apparatus or the like.
2. Related Background Art
In an information processing apparatus such as a word processor, a personal computer, or the like, a track ball is a convenient input device because the ball can be operated by the thumb irrespective of right-handed or left-handed person when it is set on this side.
However, in most of the current word processors, personal computers, and the like of the lap top type, since a palm rest is provided in front of a keyboard, there is a problem that when a track ball is arranged on this side, the palm rest cannot be used (FIG. 1). In the case where the track ball is arranged on the side of an apparatus main body as shown in FIG. 2, there is an inconvenience that it is difficult for the left-handed person to use the track ball.
In the case of the type (FIG. 3) in which the track ball is built in the apparatus main body, there is a problem that the depth dimension of the information processing apparatus main body (word processor, personal computer, or the like) is large and a dead space occurs and, when the track ball is not used, it cannot be detached.
Further, there is also a problem that when the track ball is arranged in front of the apparatus main body by attaching to the conventional word processor, personal computer, or the like of the lap top type from the outside, the palm rest cannot be used and, on the other hand, in the case where the track ball is attached to the side surface of the main body, it is 10 difficult for either the right-handed person or the left-handed person to use the track ball.
Further, in case of the conventional type in which the track ball is built in the information processing apparatus main body, there is a problem that the depth dimension of the main body is large and a dead space occurs and, when the track ball is not used, it cannot be detached.
FIG. 1 shows an example of a type in which a track ball is built in the information processing apparatus main body. In this case, however, the track ball cannot be detached and a dead space occurs, and the costs of the main body increase by an amount of the built-in track ball.
In the case where the track ball is arranged on the front or side surface as shown in FIG. 2 or 3, it is also difficult to attach the track ball to the information processing apparatus main body, and further, there is no harmony in design.
When a style of the information processing apparatus main body (word processor, personal computer, or the like) changes, it is necessary to remake the track ball in accordance with the new style.